print('%2d-%02d' % (3, 1));
print('%.2f' % 3.1415926);

print('age %.2d ,ses %s' % (20,True));

print('hello {0},成绩提升了 {1:.1f}%'.format('小李',17.234))

s1 = 72;
s2 = 85;
r = 72/85;
print('成绩提升：%.2f' % r)

